Nikon 50mm F1.2 S review – Going head-to-head against the Sigma 50mm f/1.4 Art

Mar 9, 2021

Andy Chua

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Nikon 50mm F1.2 S review – Going head-to-head against the Sigma 50mm f/1.4 Art

Mar 9, 2021

Andy Chua

We love it when our readers get in touch with us to share their stories. This article was contributed to DIYP by a member of our community. If you would like to contribute an article, please contact us here.

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Like how Nikon has been aggressively marketing the internal diameter of the Z mount being 17% larger than the Nikon F mount, the larger mount allows more flexibility in the optical design of the Z lenses just like their newest 58mm f0.95 Noct lens. Today I won’t be testing on the 58mm f0.95 as I’m not really a fan of manual focus. We will take a look into how Nikon latest 50mm F1.2 lens will hold up against the popular 3rd party lens – Sigma 50mm f/1.4 Art series.

Some basic introduction of the Sigma 50mm f/1.4 Art. Sigma has been developing some impressive lenses which are tack sharp wide open, in recent years. Apart from their bad reputation in the past for bad glass coating that causes chromatic aberration(CA) and front/back focus issue, they have been doing really well since the release of their Art series where they successfully developed lenses that could achieve tack sharp wide open at F1.4 although all their lens are quite heavy in weight. The Sigma 50mm F1.4 art has been one of my favourite workhorses for all my professional work for the past 2 years.

The Setup

Nikon Z6II and Nikon 50mm f1.2 S

Nikon Z6II and Sigma 50mm f1.4 Art with FTZ adapter

Goal of the test: I’ll be doing all my testing at F1.4 aperture to be fair to the Sigma Art. The purpose of testing at wide open instead of stopping down to F2 or F5.6 is to determine the lens sharpness wide open. If I buy an F1.4 lens and it can’t perform well wide open, I won’t see a need to consider such a lens.

*Under the courtesy of Nikon Singapore, I managed to loan both the z6ii and 50mm f1.2 S to do some test on them against my own Sigma 50mm Art copy.

Daytime Testing

For this test, my camera was mounted on the tripod to ensure the setup and the shooting distance doesn’t change. I also tried to swap the lens quick so that I could keep lighting condition to be as close as possible. I stopped down the Nikon lens to F1.4 to be fair for all the tests. The first thing I noticed with the Nikon 50mm was the frame appeared tighter than the Sigma 50mm, I would say maybe a 5% tighter in frame although both were 50mm focal length.

In terms of the focus sharpness, both lenses were equally good wide open. At 200% zoom in, I did notice the Nikon 50mm was a tad sharper on the lines against Sigma art. Having said that, both lenses performance were still pretty on par, no client will zoom in 200% to check on your images. Both lenses have what it takes to deliver your work well.

In term of bokeh, it was quite noticeable that the Nikon 50mm F1.2 S does have better glass and render bokeh much smoother than Sigma 50mm.

Along the white edges of the van, I also saw some green ‘CA’ along the white line in both lenses. The Sigma Art showed stronger green fringing than the Nikon. It’s not really a big issue in general as ‘CA’ correction in Adobe Lightroom is just one click away to get rid of the fringing.

At the extreme right corner of the Nikon 50mm F1.2 S, even after stopping down to f1.4, it produced a very pleasing bokeh at the corner. The sigma 50mm Art on the other hand has a busy looking bokeh.

Nighttime Testing

The focus for this test isn’t just about sharpness, as it will be covered in all the other tests. In the night test, I would like to compare the difference in how both lenses produce their bokeh. Who doesn’t love a creamy bokeh from a 50mm?

To test the bokeh, I placed my focus onto the metal railing so that the buildings at the back will have a shallow depth of field. The Nikon 50mm f1.2 produced a significantly larger and smoother bokeh circle at the centre and around the mid-frame than the Sigma 50mm.

At the left lower corner of the frame, the Nikon 50mm bokeh turn close to a cat’s eye shape while the Sigma 50mm Art still maintain a nice round circle shape.

At the mid-frame, the Nikon 50mm showed a better shallow depth of effect performance together with some cat’s eye bokeh effect. While the Sigma Art maintained its circle effect bokeh around the frame.

For this image, I focus on the tail light of the car so that I could get a shallow depth of field of the street lights in the background. This is a rough guide if you are doing a half-body portrait at night, that’s similar to how the bokeh might turn out.

At the mid-frame, Nikon 50mm bokeh appeared slight more blur at the long silver street lamp pole. The bokeh on Nikon 50mm also appeared to seem brighter than the Sigma 50mm.

At the top corner frame, shooting against the bright street lamp the Nikon 50mm shows a much better control towards flares than the Sigma art. This could be due to the newer coating applied to the Nikon Z lens, where both Nano Crystal and ARNEO coats are used.

How do they perform in an actual shoot?

Now time for some cute moment where I used the 50mm lenses to do some pet photography. As the dog doesn’t stay still as human do, I don’t get to shoot them in the same pose after switching my lens. The pose was slightly different but at the same focus distance.

During the dog photoshoot session, I didn’t notice any difference in terms of autofocus speed. The Nikon new 50mm Z mount focus pretty quick, I don’t really notice any major difference in focus speed compared to the Sigma 50mm.

Also kudos to Nikon for doing a really good job with their FTZ adapter now, the adapter focus relatively well even with 3rd party F mount lens just like their DSLR series. This is great for photographers who own F mount of 3rd party lens.

Both images look really great on the dog portrait session, I didn’t notice any big difference in images. Now let’s take a look into the fine details.

At 200% magnification, around the eyes area the Nikon 50mm showed a lot more details. In the eyeball, the details in the reflection details were noticeably sharper! There were also more details in the dark brown fur between the eyes on the Nikon version. On the Sigma copy, the details of the fur was slightly softer, and I don’t really see that ‘wow’ factor in term of details sharpness.

The Nikon 50mm produce a softer and smoother bokeh compare to the Sigma Art and yet maintained tack-sharp details on the dog face. When I first bought the Sigma Art, I was impressed with how they managed to produce such tack-sharp details at wide-open aperture on their Art lens. It was one of the workhorses ever since.

Now with the new optical design from Nikon Z mount, I really saw some breakthrough over there. I’m impressed once again after testing out the new 50mm F1.2. The lens produces such sharp details yet maintaining that smooth creamy bokeh.

Portraits test

Did a lens comparison during outdoor family photoshoot with dog owners as well, unfortunately, I didn’t realise that the owners actually changed their position while I was changing my lens. Other than that, focus distance still remains the same for the test.

At the mid-frame, the bokeh of the tree branches of the Sigma Art seems busy and more contrasty. I definitely prefer the Nikon 50mm for smoother and more natural bokeh.

Similarly at the corner frame where the Sigma 50mm maintain its characteristics of busy background bokeh of the street bushes.

Specification comparison

Nikon 50mm f1.2 SSigma 50mm F1.4 Art with FTZ Adapter
Lens construction17 elements in 15 groups13 elements in 8 groups
Diaphragm blades99
Dimensions89.5 x 150mm85.4 x 99.9mm + 70 x 30mm (adapter)
Minimum focus distance45cm40cm
Filter size82mm77mm
Weight1090g815g + 135g (adapter) = 950g

In terms of weight, the Nikon 50mm F1.2 S weighs 1090g and the Sigma 50mm Art with the adapter only weighs 950g in total. When Sigma Art first came out, everyone was commenting on how big and heavy their Art series was. The Sigma Art with FTZ adapter is 130mm in term of length which is 20mm shorter than the Nikon 50mm f1.2 S (150mm).

While everyone who likes to shoot with 50mm loves an F1.2 bokeh, this doesn’t just come with a higher price tag. It also comes together with a much bigger filter thread now at 82mm comparing to Sigma 77mm filter size. This means that you might need to invest in 82mm filters if you need CPL or ND filter. The larger filter will also cost slightly more than the 77mm filter.


It is quite a tough call to say Nikon is a clear winner here. In terms of specification and its performance in the real field, I’m sure it is one hell of a lens anyone would love to have. When you start to weigh in other factors like weight, dimension and filter size, Nikon’s latest 50mm F1.2 is not a lens for people with weak arms. I know there are people who would sacrifice bokeh and prefer a lighter F1.8 version then this lens is definitely not for you.

To be able to produce such high quality 50mm F1.2 lens, the price tag is also double the price of the Sigma 50mm Art F mount on B&H website. It depends on how much you treasure image quality over weight/price as one of your decision factor to get this new Nikon 50mm F1.2 S.

As for myself, its a Yay for me as I love tack sharp lenses at wide-open aperture and that F1.2 bokeh is just so lovely. This is definitely the lens that will replace the 50mm Sigma Art as my workhorse.

Photo gallery

More photos from the Nikon 50mm F1.2 S. All the photos are taken between F1.2 – F2 aperture.

About the Author

Andy is a professional photographer based in Singapore. His portfolio is 70% sports, and he has covered both local and overseas international meets. In addition to sports, he also shoots underwater photography, automotive, products, and interiors. You can find out more about Andy on his website where he has more reviews and follow his work on Instagram. This article was also published here and shared with permission.

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One response to “Nikon 50mm F1.2 S review – Going head-to-head against the Sigma 50mm f/1.4 Art”

  1. longzoom Avatar

    Wow! So good and informative test! Really much needed! Well done!